| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a positive electrode for a lithium ion secondary battery, capable of quickly dropping a voltage when a lithium secondary battery utilizing an olivine-type lithium iron phosphate particle as an active material is brought in an over discharge region (2-0.5 V). <P>SOLUTION: In a positive electrode for a lithium secondary battery, a positive electrode active material includes olivine-type lithium iron phosphate, and an average dropping speed of a discharge potential measured by the following conditions is 0.3 V/Hr or higher. Measurement conditions of an average dropping speed of a discharge potential: the measurement is performed using a two-electrode porch cell, a counter electrode of metal lithium, and 1M LiPF<SB POS="POST">6</SB>in EC+EMC+DMC=1:1:1 (vol.%) as an electrolyte, under conditions where a temperature is 30°C, a discharge range is 2-0.5 V (relative to Li/Li<SP POS="POST">+</SP>), and a discharge current is 20 mA/g-positive electrode. <P>COPYRIGHT: (C)2013,JPO&INPIT |
